Progressive supranuclear palsy (PSP) is often referred to as Steele Richardson Olszewki (SRO) syndrome, after the physicians who first presented the clinical features and neuropathology of the disorder to the American Neurological Association 50 years ago in 1963, followed by a publication in Annals of Neurology in 1964.
PSP is frequently misdiagnosed as Parkinson’s disease, but does have distinguishing clinical features, and distinction is important because treatment and prognosis are very different.
Parkinson’s disease typically presents with unilateral bradykinesia and rest tremor.
In contrast, the initial symptom of PSP is usually a gait problem (“funny walk”) including loss of balance, lunging forward when mobilizing, fast walking with difficulty stopping (festination), and falls. Other common early symptoms include changes in personality, general slowing of movement, slurred speech, difficulty swallowing and visual symptoms. In contrast to Parkinson’s disease, PSP patients have an extended (not flexed) neck, a staring “startled” facial appearance from eyelid retraction and a striking failure of voluntary vertical conjugate gaze.
Actor and comedian Dudley Moore was diagnosed with PSP in 1999, although symptoms had been present for some time before that (perhaps attributed to alcohol), and he died of pneumonia in 2002:
The pathologic hallmarks of PSP is neurofibrillary degeneration (“Tau-opathy”) and atrophy of the midbrain (see MRI images below, A&C normal, B&D PSP).
Midbrain atrophy in PSP (B,D) vs. Normal (A,C)
PSP is a progressive disease and treatment is supportive. Affected patients do not usually respond to the dopaminergic medications and surgical interventions that are so effective for treating Parkinson’s disease Physical and occupational therapy can be helpful for balance issues and avoidance of falls. Early identification of problems with swallowing should prompt referral to speech therapy for swallowing assessment and advice on appropriate measures to avoid the complications of aspiration.
Although not formally recognized as a distinct syndrome until 1963, cases of “atypical Parkinsonism” (some of them PSP) were distinguished from more typical Parkinson’s disease by Charcot in the 1880’s. The figure below shows drawings from one of Charcot’s lectures, given on June 12, 1888 contrasting a typical Parkinson’s disease patient with flexed posture (left) to an atypical Parkinsonian patient who had no tremor and an extended posture (right):
In sum, early recognition of PSP is important, since the treatment and prognosis are quite different from more typical Parkinson’s disease.
Neurology Update 